Self‐Supply of O(2) and H(2)O(2) by a Nanocatalytic Medicine to Enhance Combined Chemo/Chemodynamic Therapy

Combined chemo/chemodynamic therapy is a promising strategy to achieve an improved anticancer effect. However, the hypoxic microenvironment and limited amount of H(2)O(2) in most solid tumors severely restrict the efficacy of this treatment. Herein, the construction of a nanocatalytic medicine, CaO(2)@DOX@ZIF‐67, via a bottom‐up approach is described. CaO(2)@DOX@ZIF‐67 simultaneously supplies O(2) and H(2)O(2) to achieve improved chemo/chemodynamic therapy. In the weakly acidic environment within tumors, CaO(2)@DOX@ZIF‐67 is broken down to rapidly release the Fenton‐like catalyst Co(2+) and the chemotherapy drug doxorubicin (DOX). The unprotected CaO(2) reacts with H(2)O to generate both O(2) and H(2)O(2). The generated O(2) relieves the hypoxia in the tumor and further improve the efficacy of DOX. Meanwhile, the generated H(2)O(2) reacts with Co(2+) ions to produce highly toxic •OH through a Fenton‐like reaction, resulting in improved chemodynamic therapy.